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0 Answers

Vapor barriers & Mold

I live in a rural area (95415) without attic , only some walls with R13 insulation.

I am considering NSF certified elastomeric paint to cover shingles for the purpose of collecting rainwater for potable uses. It serves to cover toxic shingles, acts as a cool roof as well as a vapor barrier.

I am also planning on 2-3 coats of latex paint for the interior walls and ceilings of the kitchen and bathroom. This should also act as a vapor barrier.

I'm wondering if any building science folks might comment on the potential for mold potential between 2 vapor barriers.

Asked By Laura Diamondstone | Oct 2 14
10 Answers

I'm getting two different opinions about foam insulation in the attic

Some say spray the roof deck-allowing the attic air to become conditioned which is great for the H&A ducts in the attic. Others say spray the attic side or the ceiling to allow the attic to vent. I don't understand this one since the attic air is now unconditioned air and the ducts a
have only a wrap of insulation..I'm confused. Sounds like there are two schools of thought going on. Are both ways OK? Is one a lot better than the other? Help!! I even heard that the house would be too tight and allow for stale air to remain in the house if you spray the roof deck..I need answers.

Asked By Rus Pearson | Sep 30 14
3 Answers

Manual D spreadsheet examples?

Hi, I'm looking for any completed examples of the Manual D spreadsheet which is given out free from ACCA: http://www.acca.org/standards/acca-speed-sheets/

Thanks to this site for educating me on the importance of Manual J and D calculations. I know there's software for this but a) I'm cheap, and b) I'm a nerd and like to get into the details.

My hard copy of the manual is in the mail and while I wait I'd like to figure out the sheet as much as possible.

Asked By Jonathan Dalton | Oct 1 14
1 Answer

How to protect shallow mono footer during winter construction, zone 5

We have a Passive House design, which includes a shallow and 1'4'' wide mono footer. 4'' floating slab has 12'' deep thickened edges. 12'' under the slab are insulated. There are 4'' of EPS on all 3 sides of the footer. (see detail/picture).

Asked By Lucyna de Barbaro | Oct 1 14
12 Answers

Breaking thermal bridge between concrete porch and brick wall?

I have a concrete-floor porch that replaced an original wood-floor porch. It butts up right against the double-brick wall of the house (built in 1905). The house is uninsulated, so I am insulating the brick wall with rigid foam board. While I'm at it, I am thinking it is a good idea to saw-cut a 1" or 2" slot of the concrete floor right along the base of the brick wall (in other words, the floor-wall joint) to get rid of the thermal bridge that might exist, then to backfill the slot with rigid foam. Does this sound like it would make a significant difference to heat conductivity?

Asked By Paul Gorcey | Sep 26 14
12 Answers

Windows for my Pretty Good House

Hi all

Another question for the experts here at GBA--this time about what windows I should install in my Pretty Good House (PGA). I've written here before about this house and you can likely find the threads of previous questions. Basically, we're building a single level, 1700 sf house in Hood River, OR and we're trying to meet PGA and passive solar "standards". Currently, we're trying to decide what windows to put in this house, and the candidates are:

Marvin Integrity
Milgard Ultra
Intus Arcarde or Eforte

Asked By Matt Mesa | Sep 29 14
13 Answers

Grid-tied without independence … what’s the point?

Grid-tied without independence … what !?! … what’s the point …

Just read this at RMI and was shocked at the prospect that grid-tied PV systems (and probably wind, too) are not normally run by servo mechanism that locks out the network to favor independence in the event of a grid failure. That’s just dumb.

“When The Power's Out, Solar Panels May Not Keep The Lights On”

Asked By flitch plate | Sep 29 14
5 Answers

LED GU24 base bulbs

I plan to buy new lighting with GU24 2-pin sockets for my kitchen renovation. But I'm noticing many more choices of LED lights with the regular twist on base now. Will the LED GU24 base bulbs continue to have a poor pool of choices while the LED twist on consumer choices will grow? Basically I will always use LED, but I want to have the option of "nice looking" bulbs too.

Asked By Kelly Proctor | Oct 1 14
9 Answers

Hot water re-circ line & vertical head loss

Hi all,

I’m trying to size a pump for our re-circ line. We have a 1 story house, with a tankless water heater in our attic at one end of the house. Our 2 bathrooms are at the other end of the house.

Asked By Joe G | Sep 30 14
18 Answers

Detail and Insulation Review

We are looking to do REMOTE wall construction on our new house located in S.E. Michigan. Currently drawn as 2" exterior rigid foam, but 3" will probably be the the correct amount to use. I plan to use Bituthene as the WRB, not sure if anyone can recommend any alternatives? I really like Bituthene's low perms and low cost, but I assume that asphalt products aren't all that green....

Asked By Eric Burhop | Jul 31 13
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